/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

package com.eighteen12.web;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author Arif
 */
public class BaseController extends HttpServlet {
    public static final String URL_PATTERN = ".go";
    public static final String CONTROLLER_PACKAGE = "com.eighteen12.web.controller.";
    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
     * methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        Controller controller = lookupController(request);
        response.setContentType("application/json;charset=UTF-8");
        PrintWriter out = response.getWriter();
        if(controller==null){
            out.write("error getting controller");
            out.close();
            return;
        }
        Object result = controller.execute(request);
        try {
            Gson gson = new GsonBuilder().setDateFormat("dd-MMM-yyy HH:mm:ss").create();
            out.print(gson.toJson(result));
        } finally {
            out.close();
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

    private Controller lookupController(HttpServletRequest request) {
        String requestUri = request.getRequestURI();
        requestUri = requestUri.substring(request.getContextPath().length()+1, requestUri.length()-URL_PATTERN.length());
        String controllerClass = requestUri.substring(0, 1).toUpperCase() + requestUri.substring(1);
        try {
            Class clazz = Class.forName(CONTROLLER_PACKAGE+controllerClass);
            return (Controller) clazz.newInstance();
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(BaseController.class.getName()).log(Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            Logger.getLogger(BaseController.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            Logger.getLogger(BaseController.class.getName()).log(Level.SEVERE, null, ex);
        }
        return null;
    }

}
